Sr Levels Research Articles

In vitro and in vivo studies on a Mg–Sr binary alloy system developed as a new kind of biodegradable metal

Magnesium alloys have shown potential as biodegradable metallic materials for orthopedic applications due to their degradability, resemblance to cortical bone and biocompatible degradation/corrosion products. However, the fast corrosion rate and the potential toxicity of their alloying element limit the clinical application of Mg alloys. From the viewpoint of both metallurgy and biocompatibility, strontium (Sr) was selected to prepare hot rolled Mg–Sr binary alloys (with a Sr content ranging from 1 to 4wt.%) in the present study. The optimal Sr content was screened with respect to the mechanical and corrosion properties of Mg–Sr binary alloys and the feasibility of the use of Mg–Sr alloys as orthopedic biodegradable metals was investigated by in vitro cell experiments and intramedullary implantation tests. The mechanical properties and corrosion rates of Mg–Sr alloys were dose dependent with respect to the added Sr content. The as-rolled Mg–2Sr alloy exhibited the highest strength and slowest corrosion rate, suggesting that the optimal Sr content was 2wt.%. The as-rolled Mg–2Sr alloy showed Grade I cytotoxicity and induced higher alkaline phosphatase activity than the other alloys. During the 4weeks implantation period we saw gradual degradation of the as-rolled Mg–2Sr alloy within a bone tunnel. Micro-computer tomography and histological analysis showed an enhanced mineral density and thicker cortical bone around the experimental implants. Higher levels of Sr were observed in newly formed peri-implant bone compared with the control. In summary, this study shows that the optimal content of added Sr is 2wt.% for binary Mg–Sr alloys in the rolled state and that the as-rolled Mg–2Sr alloy in vivo produces an acceptable host response.

LOCAL ANALYSIS OF STRONTIUM USING FISH SCALE BY MICRO-PIXE WITH A CdTe X-RAY DETECTOR

Sr is an indicator used in studies on fish migration. In this study, the Sr profiles of ridges, which are growth lines in fish scales, in Sakhalin taimen (Hucho perryi) were examined by micro-PIXE analysis. Sakhalin taimen were reared under freshwater conditions for six months. The ridges that formed during the rearing experiment were subjected to PIXE spot analysis. This analysis was performed in a 5 X 5 μm2 area in the center region of each ridge of the scale section, and the Sr levels were calculated using the thin-section standard. The mean Sr concentration in the ridges was 428± 48 μg/g. The quantitative PIXE spot analysis successfully provided Sr profiles for the scale corresponding to ridge formation.

Investigation of Some Heavy Metal Accumulation in Water, Sediment and Carp (Cyprinus carpio) Samples of Karacaoren-II Dam Lake

In this study accumulation levels of Fe, Cu, Zn, Mn, Al, Sr, Cr, Pb, Cd, Hg was determined in water, sediment and some carp (Cyprinus carpio) tissue samples of Karacaoren-II Dam Lake between April 2009 – March 2010. Totally 24 carp have been caught and investigated seasonally. Heavy metal analysis were carried out by using ICP-OES. According to the findings; pH value varied between 7.42-8.02. In water; Cr, Cd and Hg values were below the detection limit in all seasons. Fe, Zn, Al and Sr were present almost in the whole seasons while Sr level was highest. In sediment; Fe, Zn, Mn, Al, Sr and Cr were present in all seasons while Fe was highest. Cu, Cd and Hg were below detection limit in all seasons while Pb below the detection limit in Spring. In carp tissues; Fe and Zn were determined in all seasons in whole tissues, however Cu only in Spring in liver tissues. Fe level reached highest among all metal concentrations. Cr, Cd and Hg were not determined in any tissues in all seasons. Metal concentrations were higher in the liver and gill than muscle.

Vacancy and interstitial oxide ion migration in heavily doped La2−xSrxCoO4±δ

La2−xSrxCoO4±δ, a K2NiF4-type structured oxide, is currently under investigation for its possible application as a cathode material in solid oxide fuel cells operating at intermediate temperature (IT-SOFCs). Here we report a combined energy minimization and molecular dynamics study of oxygen migration mechanisms in the La2−xSrxCoO4±δ material for high Sr levels (x > 0.8). In the oxygen-deficient composition La0.8Sr1.2CoO3.9 the oxide-ion transport mainly occurs through the migration of oxygen vacancies within the perovskite layer of the structure, with possible vacancy paths between adjacent layers. In the oxygen-rich composition La1.2Sr0.8CoO4.1 interstitial oxygen transport is via an interstitialcy mechanism and within the ab plane.

Comparative estimation of the neurotropicity of trace elements in the organism of children living in industrial towns of Ukraine

In 10- to 16-year-old children, inhabitants of industrial towns of Ukraine, an X-ray fluorescence analysis of the content of some chemical elements in hair samples allowed us to find a deficiency of Zn and Cu against the background of excesses of Ca, Cr, Ni, Mo, and Cd. Comparison of the parameters of EEG frequency components and levels of Ca, Zn, Cu, Fe, Mn, Co, Cr, Mo, Ni, Sr, Pb, and Cd showed that there are significant correlations between the normalized values of spectral powers of many frequency components of the ongoing EEG recorded in different functional states (eyes closed/open, solving an arithmetic task, and phono-/photostimulation) and concentrations of ten of the above-mentioned trace elements. Comparative estimation of the neurotropicity of the elements showed the following sequence of numbers of significant correlations (shown in parentheses) from the total set of possible comparisons: Cd (35) > Ni (31) > Cr (19) > Sr (17) > Pb (16) > > Ca (10) > Cu (7) > Mo (3) > Zn (2) > Fe (1). The intensity of correlations (values of the correlation coefficients) varied from 0.26 to 0.42 at 0.05 < P < 0.001; more frequently, such correlations were observed under conditions of EEG recording with the eyes closed (39) and upon solving an arithmetic task (33).

Restrictive Pattern in Spirometry. Does FEV1/FVC Need to Be Increased?

Introduction: Spirometry is an excellent tool in the diagnostics of airway obstruction, but is less reliable in restrictive diseases. Diagnosis of lung restriction on the grounds of reduced forced vital capacity (FVC) is burdened with many potential errors. According to the American Thoracic Society/European Respiratory Society (ATS/ERS) 2005 guidelines, restrictive pattern in spirometry consists of a reduction in vital capacity and increase in forced expiratory volume in 1 second/vital capacity (FEV1/VC) of &gt; 85–90%. However, to our knowledge, this recommendation has not been validated. The aim of this study was to check how the inclusion of an increased FEV1/FVC as a mandatory condition affects the value of spirometry in detecting a restrictive ventilatory defect. Materials and methods: The material consisted of pulmonary test results obtained from consecutive patients referred to our lab during the year 2009, who had undergone spirometry and lung volume measurements at the same visit. Results: Out of 1739 test results, there were 1402 non-obstructive cases (679 females [48.4%] and 723 males [51.6%]) with a mean age of 49.7 ± 14.5 years, included in the analysis. ERS 1993 reference equations were applied to all parameters. The lower limit of normal (LLN) was set at –1.645 of the SR level. Restrictive ventilatory defect (TLC &lt; LLN) was found in 283 patients (20.2%). Reduced FVC only, as a condition of restrictive ventilatory defect diagnosis, was found in 202 patients (14.4%) (sensitivity 59%, specificity 97%). Reduced FVC together with increased FEV1/FVC &gt; 85% was found in only 76 patients (5.4%) (sensitivity 23%, specificity 99%). Only 14% of mild, 26% of moderate, and 64% of severe restrictions could be detected with reduced FVC and increased FEV1/FVC. Conclusions: Dual condition, i.e., reduced FVC and increased FEV1/FVC, significantly diminishes the sensitivity of the test and hampers the diagnosis of restrictive ventilatory defect in spirometry, especially in mild and moderate stages.

The influence of Sr on the microstructure and texture evolution of rolled Mg–1%Zn alloy

Abstract In this study, the microstructure and texture of rolled and rolled/annealed alloys based on Mg–1 wt.%Zn and containing various levels of Sr (from 0.1 to 1.0 wt.%) were investigated. The Sr addition refined the as-cast and rolled/annealed grain structure of the Mg–1 wt.%Zn alloy. The grain refining effect of Sr is more pronounced at the lower levels of Sr than at the higher level. The as-rolled Z1 and ZJ alloys exhibit heavily deformed structures. The density of shear bands in as-rolled appears to decrease with an increase in the Sr content. Moreover, the overall texture intensity of basal poles was weakened for rolled as well as rolled/annealed Mg–Zn–Sr (ZJ) alloys compared to the Mg–1 wt.%Zn (Z1) alloy. It is noted that Sr additions expand the basal poles more in the transverse direction. The texture weakening was attributed to the particle stimulated nucleation (PSN).

Spatial pattern of natal signatures in the otoliths of juvenile kelp rockfish along the Californian coast

The natal origin of a post-dispersal marine fish may be determined by examining the trace elemental signatures present in the core (i.e. the pre-dispersal region) of the otolith. We found distinct spatial differences in the natal elemental signatures in the core region of the otoliths of post- dispersal juvenile kelp rockfish Sebastes atrovirens collected along the coast of California, USA. Laser ablation inductively coupled plasma mass spectrometry of individual otolith cores revealed detectable levels of Mn, Mg, Ba, and Sr. Using a Bayesian classification model, 2 unique elemental signature types were identified in both 2001 and 2002, and the signatures were chemically similar across years. In both years, locations received a mixture of natal types ('A' and 'B'), indicating the con- tribution of at least 2 chemically distinct sources to recruitment. The spatial pattern of the natal types varied among sites for both years. In 2001, Type A was nearly absent from the northernmost location, suggesting a southern origin and a limitation in the dispersal and contribution of this chemically iden- tified natal type. In 2002, most locations had a mix of Types A and B, but Type A was most abundant in the south and least abundant in the central part of the spatial domain. However, it was not possible to specify the full extent of dispersal of either natal type. We demonstrated use of elemental signa- tures in the otolith core of post-dispersal individuals to evaluate larval dispersal patterns which may document the extent to which kelp rockfish populations along the California coast receive recruits from different chemically distinct sources.

In the era of micro‐dissection sperm retrieval (m‐TESE) is an isolated testicular biopsy necessary in the management of men with non‐obstructive azoospermia?

To assess the outcome of sperm retrieval using micro-dissection-TESE (m-TESE) and simultaneous diagnostic biopsy in NOA to determine if the final definitive histology correlated with the outcome of sperm retrieval by m-TESE in men with NOA. To determine if there was a correlation between FSH levels and positive sperm retrieval rates and assessed the success rate of m-TESE as either a primary or a salvage procedure after previous negative sperm retrieval. The EAU guidelines (2010) recommend that in men with non obstructive azoospermia 'a testicular biopsy is the best procedure to define the histological diagnosis and the possibility of finding sperm'. However, these guidelines do not identify which patients should have a diagnostic biopsy and if this biopsy should be performed as an isolated procedure or synchronously with sperm retrieval. It is also suggested that there is a correlation between the histological diagnosis and possibility of finding sperm on testis biopsy. 100 men with NOA underwent a m-TESE sperm retrieval between 2005 and 2010 at a single centre. All patients underwent hormonal analysis (serum FSH, Testosterone and LH levels) and genetic analyses after full counselling including; Y-deletion, CF-gene analysis and karyotype. Thirty five men had previously undergone unsuccessful TESA/TESE or diagnostic biopsy at other centres. All patients underwent synchronous sperm retrieval and biopsy of the testis, which was sent for histopathological examination on the day of an ICSI cycle or as an isolated procedure. Mean age of patients was 37.25 (range 29-56 years). The mean serum FSH levels in the Sertoli cell only, maturation arrest and hypospermatogenesis groups were 21.3 IU/L (2.8-75), 16.18 (1.6-67) and 14.17 IU/L (0.8-42.3) respectively. SR rates in the respective groups were 42.85%, 26.6% and 75.86% (P= 0.023). There were no post-operative complications. In the 35 men who had previously undergone unsuccessful procedures elsewhere, the SR rates were 57.1%. The overall sperm retrieval rate was 50%. There was no correlation between SR and FSH levels (P= 0.28). M-TESE should be considered the gold standard for retrieval of testicular sperm in NOA, even in cases where there has been previously unsuccessful attempts. FSH levels and histology cannot be used to predict the success of sperm retrieval. An isolated diagnostic testicular biopsy is not recommended in men with NOA, as a significant proportion of men undergoing m-TESE will have successful a sperm retrieval irrespective of previous histology or previous unsuccessful surgery.

Microarchitecture and Nanomechanical Properties of Trabecular Bone After Strontium Administration in Osteoporotic Goats

Strontium (Sr) ralenate is a new agent used for the prevention and treatment of osteoporosis. As a bone-seeking element, 98% of Sr is deposited in the bone and teeth after oral ingestion. However, the effect of Sr treatment on bone microarchitecture and bone nanomechanical properties remains unclear. In this study, 18 osteoporotic goats were divided into four groups according to the treatment regimen: control, calcium alone (Ca), calcium and Sr at 24 mg/kg (Ca + 24Sr), and calcium and Sr at 40 mg/kg (Ca + 40Sr). The effects of Sr administration on bone microarchitecture and nanomechanical properties of trabecular bones were analyzed with micro-CT and nanoindentation test, respectively. Serum Sr levels increased six- and tenfold in the Ca + 24Sr and Ca + 40Sr groups, respectively. Similarly, Sr in the bone increased four- and sixfold in these two groups. Sr administration significantly increased trabecular bone volume fraction, trabecular thickness, and double-labeled new bone area. Sr administration, however, did not significantly change the nanomechanical properties of trabecular bone (elastic modulus and hardness). The data suggested that Sr administration increased trabecular bone volume and improved the microarchitecture while maintaining the intrinsic tissue properties in the osteoporotic goat model.

Serum biochemical markers in drowning: Diagnostic efficacy of Strontium and other trace elements

The aim of our study was to analyse several serum biochemical markers in order to evaluate the discriminant capacity of trace elements individually and jointly in drowning (seawater drowning and freshwater drowning) and their correlation with age, sex, postmortem interval, time in water and concentrations of the trace elements in the drowning medium. Sixty-seven cases of drowning (53 seawater drownings (SWD); 14 freshwater drownings (FWD) and 73 control cases (other asphyxias, n=44, and other causes of death, n=29) were selected according to the scene, cause and circumstances of death, together with autopsy findings. Serum strontium (Sr), magnesium (Mg), sodium (Na), chloride (Cl), calcium (Ca), iron (Fe), urea, creatinine (Cr) and cardiac Troponine T (cTn-T) were measured in the left ventricle (Lv), right ventricle (Rv) and peripheral blood. Lv-Rv differences for each marker and Sr, Mg, Na, Cl, Ca and Fe concentrations in the drowning medium were determinated. Mean concentrations of Sr, Cl and Mg in both ventricles and peripheral serum and Lv-Rv differences and Ca Lv and Na Rv were significantly higher in cases of drowning than for other causes of death. In SWD, Sr, Mg, Ca, Na and Cl were significantly higher in Lv than in Rv as a result of aspirating water. In contrast, haemodilution is evident from the significantly higher levels of Fe and urea in Rv than in Lv in cases of SWD, and from the higher Mg and Cr levels in Rv in FWD. In the case of SWD, serum levels of Sr are confirmed as the best parameter for diagnosis, although other trace elements may also be useful, such as the serum concentrations of Mg and Cl. In the case of FWD, the joint determination of Sr and other biochemical markers, especially Fe, may increase correct diagnosis.

Impact of treatment reduction for childhood acute lymphoblastic leukemia on serum immunoglobulins and antibodies against vaccine‐preventable diseases

The consequences of current intensive chemotherapy for childhood acute lymphoblastic leukemia (ALL) for immune defense are a matter of concern. The purpose of this study was to examine the effect of reduced compared with intensive (conventional) ALL chemotherapy on serum immunoglobulin levels and specific antibody concentrations against vaccine-preventable diseases. Patients treated according to Dutch Childhood Oncology Group ALL 10 protocol were stratified by minimal residual disease to receive reduced (standard risk; SR) or intensive (medium risk; MR) intensification/maintenance treatment. Between November 2004 and July 2009 we compared serum immunoglobulins of 110 patients and specific antibodies against diphtheria toxin, tetanus toxin, and Bordetella pertussis antigens of 41 patients of SR and MR groups during chemotherapy. Immunoglobulin levels showed significantly different patterns between the SR and MR groups. In the MR group IgG, IgA, and IgM levels decreased towards the end of intensive treatment; in the SR group IgG levels increased while IgA and IgM stabilized. In both groups IgM and IgG levels were most affected. Specific antibody levels against vaccine-preventable diseases decreased in both groups, but more profound in MR group. Although reduced chemotherapy is beneficial for immunoglobulin level recovery and might prevent susceptibility for infections, specific antibodies remain decreased.

Evaluation of elemental status of ancient human bone samples from Northeastern Hungary dated to the 10th century AD by XRF

The present study is a multielemental analysis of bone samples belonging to skeletal individuals originating from two contemporaneous (10th century AD) cemeteries (Tiszavasvári Nagy–Gyepáros and Nagycserkesz–Nádasibokor sites) in Northeastern Hungary, using the XRF analytical technique. Emitted X-rays were detected in order to determine the elemental composition of bones and to appreciate the possible influence of the burial environment on the elemental content of the human skeletal remains. Lumbar vertebral bodies were used for analysis. Applying the ED(P)XRF technique concentration of the following elements were determined: P, Ca, K, Na, Mg, Al, Cl, Mn, Fe, Zn, Br and Sr. The results indicated post mortem mineral exchange between the burial environment (soil) and bones (e.g. the enhanced levels of Fe and Mn) and referred to diagenetic alteration processes during burials. However, other elements such as Zn, Sr and Br seemed to be accumulated during the past life. On the basis of statistical analysis, clear separation could not be observed between the two excavation sites in their bone elemental concentrations which denoted similar diagenetic influences, environmental conditions. The enhanced levels of Sr might be connected with the past dietary habits, especially consumption of plant food.

Yield asymmetry and fracture behavior of Mg–3%Al–1%Zn–(0–1)%Sr alloys extruded at elevated temperatures

Tensile and compression experiments were carried on Mg–3Al–1Zn alloys containing different levels of Sr (0.05, 0.4 and 0.8 wt%) extruded at elevated temperatures of 250, 300, 350 and 400 °C and the results were compared to AZ31 alloy. The addition of 0.05 wt%Sr to the alloy produces the highest strength and the alloy containing 0.4 wt%Sr has the highest elongation during tensile tests. High levels of Sr (0.8 wt%) reduce the yield strength by decreasing the solid solubility of Al in α-Mg and thereby decreasing the solute pining effect of dislocations under both compression and tension loading. The ultimate tensile strength (UTS) is also reduced due to the cracking of Al–Sr precipitates perpendicular to the tension direction. Cracking is also seen in compressed samples; however, the cracks which initiate are parallel to the compression axis, which impedes crack opening and the formation of large voids. As a result, fracture in compression becomes less sensitive to high concentrations of Sr. It is found that increasing the extrusion temperature increases the yield asymmetry and the improvement in yield symmetry is less significant in alloys containing the high levels of Sr.

Assessment of potable water quality including organic, inorganic, and trace metal concentrations

The quality of drinking water (tap, ground, and spring) in Toyama Prefecture, Japan was assessed by studying quality indicators including major ions, total carbon, and trace metal levels. The physicochemical properties of the water tested were different depending on the water source. Major ion concentrations (Ca(2+), K(+), Si(4+), Mg(2+), Na(+), SO(4)(2-), HCO(3)(-), NO(3)(-), and Cl(-)) were determined by ion chromatography, and the results were used to generate Stiff diagrams in order to visually identify different water masses. Major ion concentrations were higher in ground water than in spring and tap water. The relationship between alkaline metals (Na(+) and K(+)), alkaline-earth metals (Ca(2+) and Mg(2+)), and HCO(3)(-) showed little difference between deep and shallow ground water. Toyama ground, spring, and tap water were all the same type of water mass, called Ca-HCO(3). The calculated total dissolved solid values were below 300 mg/L for all water sources and met World Health Organization (WHO) water quality guidelines. Trace levels of As, Cd, Cr, Co, Cu, Fe, Pb, Mn, Mo, Ni, V, Zn, Sr, and Hg were detected in ground, spring, and tap water sources using inductively coupled plasma atomic emission spectrometry, and their levels were below WHO and Japanese water quality standard limits. Volatile organic carbon compounds were quantified by headspace gas chromatography-mass spectrometry, and the measured concentrations met WHO and Japanese water quality guidelines. Total trihalomethanes (THMs) were the major contaminant detected in all natural drinking water sources, but the concentration was highest in tap water (37.27 ± 0.05 μg/L). Notably, THMs concentrations reached up to 1.1 ± 0.05 μg/L in deep ground water. The proposed model gives an accurate description of the organic, inorganic, and trace heavy metal indicators studied here and may be used in natural clean water quality management.

Microstructure, mechanical properties and texture evolution of AZ31 alloy containing trace levels of strontium

The effect of low levels of Sr (0.01, 0.03, 0.05 wt.%) on the microstructure, mechanical properties and texture of AZ31 magnesium alloy has been investigated. Thermodynamic modeling has been used to study the effect of Sr on phase precipitation at different temperatures. Cooling curve analysis reveals a decrease in solidification superheat with the addition of 0.03 wt.% Sr to AZ31. The as-cast microstructures of the alloys have been studied using optical microscopy (OM) and electron probe micro analysis (EPMA). Results show the refining effect of Sr on the grain size and on the β-Mg17Al12 precipitates through growth poisoning and inoculation, respectively. To investigate the mechanical properties of the alloys, as-cast samples were compression tested at elevated temperatures. Hot compression peak stress (σmax) and critical strain before recrystallization (εc) initially drop but then increase. σmax first decreases due to the depletion of Al from solid solution and then increases when the amount of the Al–Sr precipitates reach a significant amount. εc drops due to the acceleration of dynamic recrystallization kinetics as a result of grain refinement. It increases with increasing Sr when the concentration Sr in solid solution is increased leading to dislocation pinning and retardation of recrystallization. X-ray texture measurements on the hot compressed and extruded samples show a decrease in maximum intensity of the basal pole figures with increasing Sr as a result of reduced twining and the changes in Al and Sr concentrations in solid solution.

Altered Heat Stroke Inflammatory Responses in TNF Double Receptor Knockout Mice

Tumor necrosis factor double receptor (TNFR) knockout (KO) mice show enhanced heat stroke (HS) mortality compared to wild-type (WT; B6129F2) controls. We hypothesized that higher mortality rates are due to alterations in cytokine/soluble cytokine receptor (SR) production in the absence of TNF signaling. Plasma cytokine (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12p40, IL-12p70, IL-13, IFNγ, TNFα, MIP-1β, RANTES) and SR levels (sgp130, sIL-1RI, sIL-1RII, sIL-4R, sIL-6R, sTNFRI, sTNFRII) were examined (Luminex Multiplex™) in WT and KO mice at baseline, HS collapse, ~1h and ~4h of recovery. Baseline levels of IL-1α, IL-2, IL-4, IL-6, IL-12p70, IL-13, MIP-1α, RANTES, sIL-1RI and sIL-4R were decreased in KO compared to WT mice (ANOVA, P<0.05). IL-12p40 (collapse, 1 hour; ANOVA, P=0.030) and IL-10 (4 hour; ANOVA, P=0.034) were elevated in TNFR KO mice only. Interestingly, resolution of inflammation depends on IL-12, IL-10 and TNF interactions, which were altered in KO mice. Taken together, these results suggest that the absence of TNF signaling alters homeostatic and HS regulation of inflammation, which may account for increased mortality in TNFR KO compared to WT mice. Research supported by USAMRMC. Disclaimer: Author views not official US Army or DoD policy.

Calcium Homeostasis in Vascular Smooth Muscle Cells is altered in Type 2 Diabetes by Bcl‐2 Protein Modulation of InsP3R Calcium Release Channels

The current study examines the extent to which antiapoptotic Bcl‐2 proteins Bcl‐2 and Bcl‐XL contribute to aortic vascular smooth muscle cell (VSMC) Ca2+ dysregulation and contractility in the db/db mouse model of type 2 diabetes. Expression levels of Bcl‐XL were found to be higher in tissues isolated from diabetic (db/db) mice compared to non‐diabetic (db/m) controls. In single cells, inositol 1,4,5‐trisphosphate receptor (InsP3R)‐dependent [Ca2+]i signaling was enhanced in db/db VSMCs. This was attributed to alterations in the intrinsic properties of the InsP3R because there were no differences between db/db and db/m in the steady state [Ca2+]SR or InsP3R expression levels. Moreover, in permeabilized cells the rate of InsP3R‐dependent SR Ca2+ release was increased in db/db compared to db/m, and attenuated only in db/db cells by the Bcl‐2 protein inhibitor ABT‐737. Experiments in which [Ca2+]i and constriction were recorded simultaneously in cannulated intact arteries, application of ABT‐737 similarly attenuated enhanced agonist‐induced [Ca2+]i signaling only in intact db/db vessels. In contrast, ABT‐737 had no effect on agonist‐evoked contractility in either db/db or db/m vessels. In conclusion, elevated Bcl‐XL in diabetic VSMCs increases InsP3R excitability, the resulting dysregulated [Ca2+]i signaling, however, does not correlate with increased vessel reactivity.

Microstructure and Conductivity of La1−xSrxGa0.8Mg0.2O3−δ Electrolytes Prepared Using the Freeze-Drying Method

Polycrystalline powders of La1−xSrxGa0.8Mg0.2O3−δ (LSGM) (x=0.05, 0.10, and 0.20) were synthesized using an alternative freeze-drying method. Precursors and sintered pellets of LSGM were characterized by X-ray diffraction and scanning electron microscopy, paying special attention to the temperature dependence of phase formation and microstructure evolution. The results of this study indicate that dense LSGM samples with a low level of Sr doping x≤0.1 can be prepared as a single phase at 1300°C, although a temperature of 1400°C is required for samples with a higher Sr content (x>0.1). The phase formation and densification processes take place in a short time due to the small particle size and the low degree of agglomeration of the synthesized powders. Dense samples of La0.8Sr0.2Ga0.8Mg0.2O3−δ without secondary phases are obtained after sintering at 1400°C for only 15 min with ionic conductivity values of 0.1 S/cm at 800°C.

Comparative study of heavy metal and trace element accumulation in edible tissues of farmed and wild rainbow trout ( Oncorhynchus mykiss) using ICP-OES technique

The objective of this research was to determine the differences between farmed and wild rainbow trout in terms of heavy metal and trace element accumulation in edible tissues. The samples were analyzed for As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Se, Sr and Zn by inductively coupled plasma-optical emission spectrometry (ICP-OES); and for Hg by cold vapor atomic absorption spectrometry (CVAAS). The results were expressed as μg/g of dry weight. With the exception of Ba and Sr, liver had significantly higher heavy metal and trace element concentrations compared to the muscle in farmed or wild fish. Higher levels of Ba, Cr, Fe, Mn and Zn, as well as lower levels of Cu and Sr were found in tissues of wild rainbow trout compared to its farmed relative. Levels of Cd in 41.6% of farmed fish samples and 45.8% of wild fish samples exceeded the European Commission regulation. Regarding the Pb, concentrations in 50% of farmed fish samples and 62.5% of wild ones were above the European Commission limit. However, levels of Hg and As in all of the examined samples were lower than the legislated limits. The differences in heavy metal and trace element accumulation observed between farmed and wild fish were probably related to the differences in their environmental conditions and dietary element concentrations.